The present invention relates to a rotary waveguide coupling whose axially rotatably connected coupling members have at least one waveguide input or output, respectively.
In known rotary couplings, a rotationally symmetrical field is generated in the plane of rotation because the propagation characteristics of such a field are not influenced by the rotation. For this purpose, coaxial conductors (TEM-Type) or circular waveguides (TH.sub.01 - or TE.sub.01 -Type) are used as coupling members which are rotatable with respect to one another. Such rotary couplings are disclosed, for example, in German Pat. Nos. 2,624,428, issued Nov. 8th, 1979 and 2,134,077, issued Aug. 28th, 1975. In such rotary couplings, particularly if rectangular waveguides are used as the input or output waveguides of the rotary coupling, rather complicated transitions to the rotationally symmetrical coupling members are required. As demonstrated by German Pat. No. 2,134,077, this is primarily the case whenever the rotary coupling is of the multichannel design.
Such transitions and the measures connected therewith for mode conversion, result in an increase in the transmission attenuation of the rotary coupling and produce annoying resonances. Moreover, the rotary couplings operating according to the prior art principle are not very broadbanded, thus placing narrow limits on multichannel designs.